Ocular implant with pressure sensor and delivery system

ABSTRACT

An ocular implant including an intraocular pressure sensor and having an inlet portion and a Schlemm&#39;s canal portion distal to the inlet portion, the inlet portion being disposed at a proximal end of the implant and sized and configured to be placed within an anterior chamber of a human eye, the Schlemm&#39;s canal portion being arranged and configured to be disposed within Schlemm&#39;s canal of the eye when the inlet portion is disposed in the anterior chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.15/751,886, filed Feb. 12, 2018, which application is the national stageof International Application No. PCT/US2016/046652, filed Aug. 12, 2016,which application claims the benefit of U.S. Provisional Application No.62/205,588, filed Aug. 14, 2015, the disclosures of which areincorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure pertains generally, but not by way of limitation,to medical devices, and methods for manufacturing medical devices. Thepresent invention relates generally to devices that are implanted withinthe eye. More particularly, the present invention relates to devicesthat facilitate the transfer of fluid from within one area of the eye toanother area of the eye. Additionally, the present disclosure relates tosystems, devices and methods for delivering ocular implants into theeye.

BACKGROUND

According to a draft report by The National Eye Institute (NEI) at TheUnited States National Institutes of Health (NIH), glaucoma is now theleading cause of irreversible blindness worldwide and the second leadingcause of blindness, behind cataract, in the world. Thus, the NEI draftreport concludes, “it is critical that significant emphasis andresources continue to be devoted to determining the pathophysiology andmanagement of this disease.” Glaucoma researchers have found a strongcorrelation between high intraocular pressure and glaucoma. For thisreason, eye care professionals routinely screen patients for glaucoma bymeasuring intraocular pressure using a device known as a tonometer. Manymodern tonometers make this measurement by blowing a sudden puff of airagainst the outer surface of the eye.

The eye can be conceptualized as a ball filled with fluid. There are twotypes of fluid inside the eye. The cavity behind the lens is filled witha viscous fluid known as vitreous humor. The cavities in front of thelens are filled with a fluid know as aqueous humor. Whenever a personviews an object, he or she is viewing that object through both thevitreous humor and the aqueous humor.

Whenever a person views an object, he or she is also viewing that objectthrough the cornea and the lens of the eye. In order to be transparent,the cornea and the lens can include no blood vessels. Accordingly, noblood flows through the cornea and the lens to provide nutrition tothese tissues and to remove wastes from these tissues. Instead, thesefunctions are performed by the aqueous humor. A continuous flow ofaqueous humor through the eye provides nutrition to portions of the eye(e.g., the cornea and the lens) that have no blood vessels. This flow ofaqueous humor also removes waste from these tissues.

Aqueous humor is produced by an organ known as the ciliary body. Theciliary body includes epithelial cells that continuously secrete aqueoushumor. In a healthy eye, a stream of aqueous humor flows out of theanterior chamber of the eye through the trabecular meshwork and intoSchlemm's canal as new aqueous humor is secreted by the epithelial cellsof the ciliary body. This excess aqueous humor enters the venous bloodstream from Schlemm's canal and is carried along with the venous bloodleaving the eye.

When the natural drainage mechanisms of the eye stop functioningproperly, the pressure inside the eye begins to rise. Researchers havetheorized prolonged exposure to high intraocular pressure causes damageto the optic nerve that transmits sensory information from the eye tothe brain. This damage to the optic nerve results in loss of peripheralvision. As glaucoma progresses, more and more of the visual field islost until the patient is completely blind.

In addition to drug treatments, a variety of surgical treatments forglaucoma have been performed. For example, shunts were implanted todirect aqueous humor from the anterior chamber to the extraocular vein(Lee and Scheppens, “Aqueous-venous shunt and intraocular pressure,”Investigative Opthalmology (February 1966)). Other early glaucomatreatment implants led from the anterior chamber to a sub-conjunctivalbleb (e.g., U.S. Pat. Nos. 4,968,296 and 5,180,362). Still others wereshunts leading from the anterior chamber to a point just insideSchlemm's canal (Spiegel et al., “Schlemm's canal implant: a new methodto lower intraocular pressure in patients with POAG?” Ophthalmic Surgeryand Lasers (June 1999); U.S. Pat. Nos. 6,450,984; 6,450,984.

SUMMARY

This disclosure provides design, material, and manufacturing methodalternatives for medical devices.

In a first example, an ocular implant adapted to reside at leastpartially in a portion of Schlemm's canal of an eye may comprise atubular body having an inner surface and an outer surface, the tubularbody extending in a curved volume whose longitudinal axis forms an arcof a circle; a plurality of open areas and strut areas formed in thetubular body, the strut areas surrounding the plurality of open areas; apressure sensor disposed on the inner surface of the tubular body; andthe tubular body having a diameter of between 0.005 inches and 0.04inches.

Alternatively or additionally to any of the embodiments above, thepressure sensor comprises a micro-electro-mechanical system (MEMS)pressure sensor.

Alternatively or additionally to any of the embodiments above, thepressure sensor includes an antenna for transmitting data from thepressure sensor to a remote location.

Alternatively or additionally to any of the embodiments above, the datais automatically transmitted from the remote location to a second remotedevice.

Alternatively or additionally to any of the embodiments above, the strutareas are connected by one or more spine areas.

Alternatively or additionally to any of the embodiments above, eachstrut area undulates in a circumferential direction as it extendslongitudinally between a first spine area and a second spine area.

Alternatively or additionally to any of the embodiments above, theimplant is formed from shape memory material in a shape approximatelyequal to the curved volume.

Another example system comprises a cannula defining a passagewayextending from a proximal end to a distal end, the cannula having adistal opening extending through a side wall and the distal end of thecannula to form a trough, a curved distal portion, a curved intermediateportion, and a proximal portion, the cannula further including a firstpressure sensor disposed within the trough; an ocular implant disposedwithin the passageway of the cannula; and a delivery tool having adistal interlocking portion engaging a complementary interlockingportion of the ocular implant.

Alternatively or additionally to any of the embodiments above, the firstpressure sensor comprises a micro-electro-mechanical system (MEMS)pressure sensor.

Alternatively or additionally to any of the embodiments above, the firstpressure sensor includes an antenna for transmitting data from the firstpressure sensor to a remote location.

Alternatively or additionally to any of the embodiments above, furthercomprising a second pressure sensor disposed on or within the ocularimplant.

Alternatively or additionally to any of the embodiments above, thesecond pressure sensor comprises a micro-electro-mechanical system(MEMS) pressure sensor.

Alternatively or additionally to any of the embodiments above, thesecond pressure sensor includes an antenna for transmitting data fromthe second pressure sensor to a remote location.

Alternatively or additionally to any of the embodiments above, thedistal interlocking portion of the delivery tool and the complementaryinterlocking portion of the ocular implant form a mechanicallyinterlocking connection when the interlocking portion of the deliverytool is proximal to the trough of the cannula.

Another example ocular implant kit comprises an ocular implant adaptedto reside at least partially in a portion of Schlemm's canal of an eye,the implant comprising a tubular body having an inner surface and anouter surface, the tubular body extending in a curved volume whoselongitudinal axis forms an arc of a circle; and a plurality of openareas and strut areas formed in the tubular body, the strut areassurrounding the plurality of open areas; a first pressure sensordisposed on the inner surface of the tubular body; and the tubular bodyhaving a diameter of between 0.005 inches and 0.04 inches. The kitfurther comprising a cannula defining a passageway extending from aproximal end to a distal end, the cannula having a distal openingextending through a side wall and the distal end of the cannula to forma trough, a curved distal portion, a curved intermediate portion, and aproximal portion; and a delivery tool having a distal interlockingportion engaging a complementary interlocking portion of the ocularimplant.

Alternatively or additionally to any of the embodiments above, the firstpressure sensor comprises a micro-electro-mechanical system (MEMS)pressure sensor.

Alternatively or additionally to any of the embodiments above, the firstpressure sensor includes an antenna for transmitting data from the firstpressure sensor to a remote location.

Alternatively or additionally to any of the embodiments above, the datais automatically transmitted from the remote location to a second remotedevice.

Alternatively or additionally to any of the embodiments above, furthercomprising a second pressure sensor disposed within the trough of thecannula.

Alternatively or additionally to any of the embodiments above, thesecond pressure sensor comprises a micro-electro-mechanical system(MEMS) pressure sensor and includes an antenna for transmitting datafrom the second pressure sensor to a remote location.

The above summary of some examples and embodiments is not intended todescribe each disclosed embodiment or every implementation of thepresent disclosure. The Brief Description of the Drawings, and DetailedDescription, which follow, more particularly exemplify theseembodiments, but are also intended as exemplary and not limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of thefollowing detailed description of various embodiments in connection withthe accompanying drawings, in which:

FIG. 1 is a stylized perspective view depicting a portion of a human eyeand a portion of an ocular implant disposed in Schlemm's canal.

FIG. 2 is an enlarged perspective view showing a portion of the implantof FIG. 1.

FIG. 3 is a perspective view showing a volume defined by the body of theocular implant of FIGS. 1 and 2.

FIG. 4 is a perspective view showing a first plane intersecting the bodyof an ocular implant.

FIG. 5 is a perspective view showing a bending moment being applied toan ocular implant.

FIG. 6 is a plan view of the implant shown in FIG. 5 but in the absenceof any bending moment.

FIG. 7A is a lateral cross-sectional view of the ocular implant of FIG.6 taken along section line A-A of FIG. 6.

FIG. 7B is a lateral cross-sectional view of the ocular implant of FIG.6 taken along section line B-B of FIG. 6.

FIG. 8 is an enlarged cross-sectional view of the ocular implant of FIG.6 taken along section line B-B of FIG. 6.

FIG. 9 is an enlarged cross-sectional view of the ocular implant of FIG.6 taken along section line A-A of FIG. 6.

FIG. 10A is an enlarged perspective view of a portion of the ocularimplant including a pressure sensor.

FIG. 10B is a cross-sectional view of the illustrative pressure sensorof FIG. 10A, taken at line B-B.

FIG. 10C is an enlarged perspective view of another portion of theocular implant including a pressure sensor.

FIG. 11 is stylized view of an electronic device receiving data from animplanted ocular implant.

FIG. 12 is a plan view showing an ocular implant according to anotherembodiment of the invention having a longitudinal radius of curvaturethat varies along its length.

FIG. 13 is a perspective view showing an ocular implant according to yetanother embodiment of the invention that has substantially no radius ofcurvature.

FIG. 14 is a stylized representation of a medical procedure inaccordance with this Detailed Description.

FIG. 15 is an enlarged perspective view further illustrating thedelivery system and the eye shown in FIG. 14.

FIG. 16A is a perspective view showing a delivery system including anocular implant and a cannula defining a passageway that is dimensionedto slidingly receive the ocular implant.

FIG. 16B is an enlarged detail view further illustrating the ocularimplant and the cannula 108 shown in FIG. 6A.

FIG. 17 is a perspective view of a cannula in accordance with thedetailed description.

FIG. 18 is a perspective view of an assembly including the cannula shownin FIG. 17 and an ocular implant that is resting in a passageway definedby the cannula.

FIG. 19 is a stylized perspective view including the assembly shown inFIG. 18.

FIG. 20 is an enlarged perspective view showing a portion of the cannulashown in the assembly of FIG. 19.

FIG. 21 is an additional perspective view showing the ocular implant andthe cannula shown in the previous FIG. 20.

FIG. 22 is an additional perspective view showing the ocular implant andthe cannula shown in FIG. 21.

FIG. 23 is an additional perspective view showing the ocular implant andthe cannula shown in FIGS. 21 and 22.

FIG. 24 is a perspective view of Schlemm's canal after the cannula shownin FIG. 23 has been withdrawn leaving an inlet portion of the ocularimplant in the anterior chamber of the eye and the remainder of ocularimplant in Schlemm's canal.

FIG. 25A is a perspective view showing another illustrative deliverysystem including an ocular implant and a cannula defining a passagewaythat is dimensioned to slidingly receive the ocular implant.

FIG. 25B is an enlarged detail view further illustrating the ocularimplant and the cannula shown in FIG. 25A.

FIG. 26 is an enlarged perspective view further illustrating thedelivery system shown in FIG. 25 and an eye.

FIG. 27 is a perspective view further illustrating delivery system shownin FIG. 25.

FIG. 28 is a side view further illustrating the cannula shown in FIG.25.

FIG. 28A is an additional side view illustrating the cannula shown inFIG. 25.

FIG. 29 is an enlarged detail view further illustrating the cannulashown in FIG. 25.

FIG. 30 is an enlarged perspective view further illustrating the distalportion of the cannula shown in FIG. 25.

While the disclosure is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that the intention is not to limit the invention tothe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the disclosure.

DETAILED DESCRIPTION

The following description should be read with reference to the drawings,which are not necessarily to scale, wherein like reference numeralsindicate like elements throughout the several views. The detaileddescription and drawings are intended to illustrate but not limit theclaimed invention. Those skilled in the art will recognize that thevarious elements described and/or shown may be arranged in variouscombinations and configurations without departing from the scope of thedisclosure. The detailed description and drawings illustrate exampleembodiments of the claimed invention.

Definitions of certain terms are provided below and shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about,” whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same or substantiallythe same function or result). In many instances, the terms “about” mayinclude numbers that are rounded to the nearest significant figure.Other uses of the term “about” (i.e., in a context other than numericvalues) may be assumed to have their ordinary and customarydefinition(s), as understood from and consistent with the context of thespecification, unless otherwise specified.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include or otherwise refer to singular aswell as plural referents, unless the content clearly dictates otherwise.As used in this specification and the appended claims, the term “or” isgenerally employed to include “and/or,” unless the content clearlydictates otherwise.

It is noted that references in the specification to “an embodiment”,“some embodiments”, “other embodiments”, etc., indicate that theembodiment(s) described may include a particular feature, structure, orcharacteristic, but every embodiment may not necessarily include theparticular feature, structure, or characteristic. Moreover, such phrasesare not necessarily referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with an embodiment, it would be within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments, whether or not explicitlydescribed, unless clearly stated to the contrary. That is, the variousindividual elements described below, even if not explicitly shown in aparticular combination, are nevertheless contemplated as beingcombinable or able to be arranged with each other to form otheradditional embodiments or to complement and/or enrich the describedembodiment(s), as would be understood by one of ordinary skill in theart.

The following detailed description should be read with reference to thedrawings, in which similar elements in different drawings are identifiedwith the same reference numbers. The drawings, which are not necessarilyto scale, depict illustrative embodiments and are not intended to limitthe scope of the disclosure.

FIG. 1 is a stylized perspective view depicting a portion of a human eye20. Eye 20 can be conceptualized as a fluid filled ball having twochambers. Sclera 22 of eye 20 surrounds a posterior chamber 24 filledwith a viscous fluid known as vitreous humor. Cornea 26 of eye 20encloses an anterior chamber 30 that is filled with a fluid know asaqueous humor. The cornea 26 meets the sclera 22 at a limbus 28 of eye20. A lens 32 of eye 20 is located between anterior chamber 30 andposterior chamber 24. Lens 32 is held in place by a number of ciliaryzonules 34. Whenever a person views an object, he or she is viewing thatobject through the cornea, the aqueous humor, and the lens of the eye.In order to be transparent, the cornea and the lens can include no bloodvessels. Accordingly, no blood flows through the cornea and the lens toprovide nutrition to these tissues and to remove wastes from thesetissues. Instead, these functions are performed by the aqueous humor. Acontinuous flow of aqueous humor through the eye provides nutrition toportions of the eye (e.g., the cornea and the lens) that have no bloodvessels. This flow of aqueous humor also removes waste from thesetissues.

Aqueous humor is produced by an organ known as the ciliary body. Theciliary body includes epithelial cells that continuously secrete aqueoushumor. In a healthy eye, a stream of aqueous humor flows out of the eyeas new aqueous humor is secreted by the epithelial cells of the ciliarybody. This excess aqueous humor enters the blood stream and is carriedaway by venous blood leaving the eye.

In a healthy eye, aqueous humor flows out of the anterior chamber 30through the trabecular meshwork 36 and into Schlemm's canal 38, locatedat the outer edge of the iris 42. Aqueous humor exits Schlemm's canal 38by flowing through a number of outlets 40. After leaving Schlemm's canal38, aqueous humor is absorbed into the venous blood stream.

In FIG. 1, an ocular implant 100 is disposed in Schlemm's canal 38 ofeye 20. Ocular implant 100 has a body 102 including a plurality oftissue supporting frames 104 and a plurality of spines 106. Body 102also includes a first edge 120 and a second edge 122 that define a firstopening 124. First opening 124 is formed as a slot and fluidlycommunicates with an elongate channel 126 defined by an inner surface128 of body 102. With reference to FIG. 1, it will be appreciated thatfirst opening 124 is disposed on an outer side 130 of body 102.Accordingly, channel 126 opens in a radially outward direction 132 viafirst opening 124.

Ocular implant 100 may be inserted into Schlemm's canal of a human eyeto facilitate the flow of aqueous humor out of the anterior chamber.This flow may include axial flow along Schlemm's canal, flow from theanterior chamber into Schlemm's canal, and flow leaving Schlemm's canalvia outlets communicating with Schlemm's canal. When in place within theeye, ocular implant 100 will support trabecular mesh tissue andSchlemm's canal tissue and will provide for improved communicationbetween the anterior chamber and Schlemm's canal (via the trabecularmeshwork) and between pockets or compartments along Schlemm's canal. Asshown in FIG. 1, the implant is preferably oriented so that the firstopening 124 is disposed radially outwardly within Schlemm's canal.

FIG. 2 is an enlarged perspective view showing a portion of ocularimplant 100 shown in the previous figure. Ocular implant 100 has a body102 that extends along a generally curved longitudinal axis 134. Body102 has a plurality of tissue supporting frames 104 and a plurality ofspines 106. As shown in FIG. 2, these spines 106 and frames 104 arearranged in a repeating AB pattern in which each A is a tissuesupporting frame and each B is a spine. In the embodiment of FIG. 2, onespine extends between each adjacent pair of frames 104

The frames 104 of body 102 include a first frame 136 of ocular implant100 that is disposed between a first spine 140 and a second spine 142.In the embodiment of FIG. 2, first frame 136 is formed as a first strut144 that extends between first spine 140 and second spine 142. Firstframe 136 also includes a second strut 146 extending between first spine140 and second spine 142. In the exemplary embodiment of FIG. 2, eachstrut undulates in a circumferential direction as it extendslongitudinally between first spine 140 and second spine 142.

In the embodiment of FIG. 2, body 102 has a longitudinal radius 150 anda lateral radius 148. Body 102 of ocular implant 100 includes a firstedge 120 and a second edge 122 that define a first opening 124. Firstopening 124 fluidly communicates with an elongate channel 126 defined byan inner surface 128 of body 102. A second opening 138 is defined by asecond edge 122A of a first strut 144 and a second edge 122B of a secondstrut 146. First opening 124, second opening 138 and additional openingsdefined by ocular implant 100 allow aqueous humor to flow laterallyacross and/or laterally through ocular implant 100. The outer surfacesof body 102 define a volume 152.

FIG. 3 is an additional perspective view showing volume 152 defined bythe body of the ocular implant shown in the previous figure. Withreference to FIG. 3, it will be appreciated that volume 152 extendsalong a generally curved longitudinal axis 134. Volume 152 has alongitudinal radius 150, a lateral radius 148, and a generally circularlateral cross section 153.

FIG. 4 is a perspective view showing a first plane 154 and a secondplane 155 that both intersect ocular implant 100. In FIG. 4, first plane154 is delineated with hatch marks. With reference to FIG. 4, it will beappreciated that spines 106 of body 102 are generally aligned with oneanother and that first plane 154 intersects all spines 106 shown in FIG.4. In the embodiment of FIG. 4, body 102 of ocular implant 100 isgenerally symmetric about first plane 154.

In the embodiment of FIG. 4, the flexibility of body 102 is at a maximumwhen body 102 is bending along first plane 154, and body 102 has lessflexibility when bending along a plane other than first plane 154 (e.g.,a plane that intersects first plane 154). For example, in the embodimentshown in FIG. 4, body 102 has a second flexibility when bending alongsecond plane 155 that is less than the first flexibility that body 102has when bending along first plane 154.

Stated another way, in the embodiment of FIG. 4, the bending modulus ofbody 102 is at a minimum when body 102 is bent along first plane 154.Body 102 has a first bending modulus when bent along first plane 154 anda greater bending modulus when bent along a plane other than first plane154 (e.g., a plane that intersects first plane 154). For example, in theembodiment shown in FIG. 4, body 102 has a second bending modulus whenbent along second plane 155 that is greater than the first bendingmodulus that body 102 has when bent along first plane 154.

FIG. 5 is an enlarged perspective view showing a portion of ocularimplant 100 shown in the previous figure. In the exemplary embodiment ofFIG. 5, a bending moment M is being applied to body 102 of ocularimplant 100. Bending moment M acts about a first axis 156 that isgenerally orthogonal to first plane 154. A second axis 158 and a thirdaxis 160 are also shown in FIG. 5. Second axis 158 is generallyperpendicular to first axis 156. Third axis 160 is skewed relative tofirst axis 156.

An inner surface 128 of body 102 defines a channel 126. Body 102 ofocular implant 100 includes a first edge 120 and a second edge 123 thatdefine a first opening 124. Channel 126 of ocular implant 100 fluidlycommunicates with first opening 124. A second opening 138 is defined bya second edge 122A of a first strut 144 and a second edge 122B of asecond strut 146. First opening 124, second opening 138 and additionalopenings defined by ocular implant 100 allow aqueous humor to flowlaterally across and/or laterally through ocular implant 100.

As shown in FIG. 5, ocular implant 100 has a first spine 140 and asecond spine 142. First strut 144 and a second strut 146 form a firstframe 136 of ocular implant 100 that extends between first spine 140 andsecond spine 142. In the exemplary embodiment of FIG. 5, each strutundulates in a circumferential direction as it extends longitudinallybetween first spine 140 and second spine 142.

In the embodiment of FIG. 5, the flexibility of body 102 is at a maximumwhen body 102 is bent by a moment acting about first axis 156, and body102 has less flexibility when bent by a moment acting about an axisother than first axis 156 (e.g., second axis 158 and third axis 160).Stated another way, the bending modulus of body 102 is at a minimum whenbody 102 is bent by a moment acting about first axis 156, and body 102has a greater bending modulus when bent by a moment acting about an axisother than first axis 156 (e.g., second axis 158 and third axis 160).

FIG. 6 is a plan view showing ocular implant 100 shown in the previousfigure. In the embodiment of FIG. 6, no external forces are acting onbody 102 of ocular implant 100, and body 102 is free to assume thegenerally curved resting shape depicted in FIG. 6. Body 102 defines afirst opening 124 that is disposed on an outer side 130 of body 102. Achannel 126 is defined by the inner surface of body 102 and opens in aradially outward direction 132 via first opening 124. A proximal end 101of the ocular implant 100 may include an interlocking portion configuredto mate with and/or engage a complementary interlocking portion of adelivery tool. Section lines A-A and B-B are visible in FIG. 6. Sectionline A-A intersects a first frame 136 of ocular implant 100. Sectionline B-B intersects a first spine 140 of ocular implant 100.

FIG. 7A is a lateral cross-sectional view of ocular implant 100 takenalong section line A-A shown in the previous figure. Section line A-Aintersects a first strut 144 and a second strut 146 of first frame 136at the point where the circumferential undulation of these struts is atits maximum. Body 102 of ocular implant 100 has a longitudinal radius150 and a lateral radius 148. An inner surface 128 of body 102 defines achannel 126. A first opening 124 fluidly communicates with channel 126.

In FIG. 7A, first opening 124 in body 102 can be seen extending betweenfirst edge 120A of first strut 144 and a first edge 120B of second strut146. With reference to FIG. 7A, it will be appreciated that second strut146 has a shape that is a mirror image of the shape of first strut 144.

FIG. 7B is a lateral cross-sectional view of ocular implant 100 takenalong section line B-B shown in the previous figure. Section line B-Bintersects first spine 140 of ocular implant 100. Body 102 has alongitudinal radius 150 and a lateral radius 148. In the embodiment ofFIG. 7B, the center 159 of lateral radius 148 and the center 163 oflongitudinal radius 150 are disposed on opposite sides of first spine140. The center 159 of lateral radius 148 is disposed on a first side offirst spine 140. The center 163 of longitudinal radius 150 is disposedon a second side of second spine 142.

FIG. 8 is an enlarged cross-sectional view of ocular implant 100 takenalong section line B-B of FIG. 6. First spine 140 includes a first majorside 161, a second major side 162, a first minor side 164, and secondminor side 166. With reference to FIG. 8, it will be appreciated thatfirst major side 161 comprises a concave surface 168. Second major side162 is opposite first major side 161. In the embodiment of FIG. 8,second major side 162 comprises a convex surface 170.

The geometry of the spine provides the ocular implant with flexibilitycharacteristics that may aid in advancing the ocular implant intoSchlemm's canal. In the embodiment of FIG. 8, first spine 140 has athickness T1 extending between first major side 161 and second majorside 162. Also in the embodiment of FIG. 8, first spine 140 has a widthW1 extending between first minor side 164 and second minor side 166.

In some useful embodiments, the spine of an ocular implant in accordancewith this detailed description has an aspect ratio of width W1 tothickness T1 greater than about 2. In some particularly usefulembodiments, the spine of an ocular implant in accordance with thisdetailed description has an aspect ratio of width W1 to thickness T1greater than about 4. In one useful embodiment, the ocular implant has aspine with an aspect ratio of width W1 to thickness T1 of about 5.2.

A first axis 156, a second axis 158 and a third axis 160 are shown inFIG. 8. Second axis 158 is generally perpendicular to first axis 156.Third axis 160 is skewed relative to first axis 156.

In the embodiment of FIG. 8, the flexibility of first spine 140 is at amaximum when first spine 140 is bent by a moment acting about first axis156. First spine 140 has a first flexibility when bent by a momentacting about first axis 156 and less flexibility when bent by a momentacting about an axis other than first axis 156 (e.g., second axis 158and third axis 160). For example, first spine 140 has a secondflexibility when bent by a moment acting about second axis 158 shown inFIG. 8. This second flexibility is less than the first flexibility thatfirst spine 140 has when bent by a moment acting about first axis 156.

In the embodiment of FIG. 8, the bending modulus of first spine 140 isat a minimum when first spine 140 is bent by a moment acting about firstaxis 156. First spine 140 has a first bending modulus when bent by amoment acting about first axis 156 and a greater bending modulus whenbent by a moment acting about an axis other than first axis 156 (e.g.,second axis 158 and third axis 160). For example, first spine 140 has asecond bending modulus when bent by a moment acting about second axis158 shown in FIG. 8. This second bending modulus is greater than thefirst bending modulus that first spine 140 has when bent by a momentacting about first axis 156.

FIG. 9 is an enlarged cross-sectional view of ocular implant 100 takenalong section line A-A of FIG. 6. Section line A-A intersects firststrut 144 and second strut 146 at the point where the circumferentialundulation of these struts is at its maximum.

Each strut shown in FIG. 9 includes a first major side 161, a secondmajor side 162, a first minor side 164, and second minor side 166. Withreference to FIG. 9, it will be appreciated that each first major side161 comprises a concave surface 168 and each second major side 162comprises a convex surface 170.

In the embodiment of FIG. 9, each strut has a thickness T2 extendingbetween first major side 161 and second major side 162. Also in theembodiment of FIG. 9, each strut has a width W2 extending between firstminor side 164 and second minor side 166. In some useful embodiments, anocular implant in accordance with this detailed description includesspines having a width W1 that is greater than the width W2 of the strutsof the ocular implant.

In some useful embodiments, the struts of an ocular implant inaccordance with this detailed description have an aspect ratio of widthW2 to thickness T2 greater than about 2. In some particularly usefulembodiments, the struts of an ocular implant in accordance with thisdetailed description have an aspect ratio of width W2 to thickness T2greater than about 4. One exemplary ocular implant has struts with anaspect ratio of width W2 to thickness T2 of about 4.4.

Body 102 of ocular implant 100 has a longitudinal radius 150 and alateral radius 148. In some useful embodiments, an ocular implant inaccordance with this detailed description is sufficiently flexible toassume a shape matching the longitudinal curvature of Schlemm's canalwhen the ocular implant advanced into the eye. Also in some usefulembodiments, a length of the ocular implant is selected so that theimplant will extend across a pre-selected angular span when the implantis positioned in Schlemm's canal. Examples of pre-selected angular spansthat may be suitable in some applications include 60°, 90°, 150° and180°. The diameter of an ocular implant in accordance with this detaileddescription may be selected so that the ocular implant is dimensioned tolie within and support Schlemm's canal. In some useful embodiments, thediameter of the ocular implant ranges between about 0.005 inches (0.127millimeters) and about 0.04 inches (1.016 millimeters). In someparticularly useful embodiments, the diameter of the ocular implantranges between about 0.005 inches (0.127 millimeters) and about 0.02inches (0.508 millimeters).

It is to be appreciated that an ocular implant in accordance with thepresent detailed description may be straight or curved. If the ocularimplant is curved, it may have a substantially uniform longitudinalradius throughout its length, or the longitudinal radius of the ocularimplant may vary along its length. FIG. 6 shows one example of an ocularimplant having a substantially uniform radius of curvature. FIG. 10shows one example of an ocular implant having a longitudinal radius ofcurvature that varies along the length of the ocular implant. An exampleof a substantially straight ocular implant is shown in FIG. 13.

FIG. 10A is an enlarged perspective view showing a portion of ocularimplant 100 shown in the FIGS. 2 and 4. The ocular implant 100 mayfurther include an intraocular pressure sensor 180 mounted to the innersurface 128 of the ocular implant 100 adjacent to an outlet of theimplant 100, as shown in Detail A. While the pressure sensor 180 isillustrated as mounted to an inner surface 128 of the ocular implant 100it is contemplated that the pressure sensor 180 may be mounted withinone of the openings 124, 138 or on an outer surface of the ocularimplant 100, as desired. The pressure sensor 180 may continuouslymeasure the intraocular pressure of a patient, once the ocular implant100 has been implanted.

The pressure sensor 180 may be a Micro-Electro-Mechanical System (MEMS)pressure sensor. While the pressure sensor 180 has been described as aMEMS pressure sensor, it is contemplated that other pressure sensors maybe used in place of, or in addition to, a MEMS pressure sensor. In someinstances, the pressure sensor 180 may have a width in the range ofapproximately 0.02 millimeters (20 micrometers) to approximately 1.0millimeters. However, it is contemplated that the pressure sensors 180are smaller than 20 micrometers, or larger than 1.0 millimeter. In someinstances, the pressure sensor 180 may have a width dimension in thenanometer range. Further, while only a single pressure sensor 180 hasbeen illustrated, the ocular implant 100 may include more than onepressure sensor 180, as desired. For example, a first pressure sensormay be placed at a first end of the ocular implant 100 and a secondpressure sensor may be placed at a second end of the ocular implant. Insome instances, the pressure sensor 180 may be provided in the channel128 adjacent to the proximal end 101 of the implant 100, as shown inFIG. 10C. It is contemplated that the pressure sensor 180 may include aprotective cover to prevent the delivery device (not explicitly shown)from damaging the sensor 180 during delivery of the ocular implant 100,although this is not required.

MEMS pressure sensors are often formed by anisotropically etching arecess into a back side of a silicon substrate die, leaving a thinflexible diaphragm 182. In operation, at least one surface of thediaphragm 182 is exposed to an input pressure (e.g., the ocularpressure). The diaphragm 182 deflects according to the magnitude of theinput pressure, which may be detected by one or more electricalcomponents or sense elements 186 (e.g., piezoresistors) positioned on orembedded within the diaphragm 182. The change in resistance of thepiezoresistors 186 is reflected as a change in an output voltage signalfrom a resistive bridge formed at least in part by the piezoresistors.In some cases, the diaphragm may be made thinner with the addition ofsupport bosses, which may help increase the sensitivity of the diaphragmover a flat plate diaphragm. Circuit elements may be connected so thatsensor elements 186 to provide some level of signal processing beforeproviding an output signal to bond pads 188 of the pressure sensor 180.The signal processing may filter, amplify, linearize, calibrate and/orotherwise process the raw sensor signal produced by the sensor elements(e.g., piezoresistors 186). While the sense elements 186 have beendescribed as piezoresistors, it is contemplated that the sense elementsmay be selected to provide a capacitive pressure sensor 180.

The pressure sensor 180 may include a first substrate 185 and a secondsubstrate 183, as shown in FIG. 10B, which is a cross-section of theillustrative pressure sensor 180 taken at line B-B in FIG. 10A. In someinstances, the first substrate 185 may be a layeredsilicon-insulator-silicon substrate or wafer formed with silicon oninsulator (SOI) technology, although this is not required. It iscontemplated that other substrates may be used, as desired. The firstsubstrate 185 may include a first silicon layer. An insulating, oroxide, layer 187 may be disposed on the first silicon layer 185. In someinstances, the insulating layer 187 may be formed from silicon dioxide,silicon nitride, sapphire, and/or any other suitable insulatingmaterial. While not explicitly shown, the pressure sensor 180 mayinclude a second silicon layer disposed on the insulating layer. In someinstances, the second silicon layer may be thinned or removed such thatthe oxide layer 187 is exposed at the side facing away from the secondsubstrate 183. Alternatively, and in some cases, the second siliconlayer and oxide layer 187 are not provided from the start.

The second substrate 183 may be any semi-conductor wafer (e.g., siliconor germanium) or other substrate as desired. It is contemplated thateither or both the first substrate 185 or the second substrate 183 maybe doped with an impurity to provide an n-type or p-type extrinsicsemiconductor. For example, the first substrate 185 may be an n-typesubstrate while the second substrate 183 may be a p-type substrate. Thereverse configuration is also contemplated, or both substrates may bedoped the same polarity. In some instances, the first substrate 185and/or the second substrate 183 may include an epitaxial layer.

A portion of the first substrate 185, such as a portion of the firstsilicon layer, may be removed, leaving a thin, flexible diaphragm 182over a cavity or recess 181. In some cases, piezoresistors 186 may belocated in or on the diaphragm 182 to measure deflection/stress of thediaphragm 182 to form a pressure sensor. During operation, at least onesurface of the diaphragm 182 may be exposed to an input pressure. Thediaphragm 182 may then deflect according to a magnitude of the pressureon the diaphragm 182. A deflection of the diaphragm 182 then createschanges in resistance in the piezoresistors 186. A change in resistanceof the piezoresistors 186 may be reflected as a change in an outputvoltage signal of a resistive bridge that is formed at least partiallyby the piezoresistors 186. The output voltage provides a measure of theinput pressure exerted on the diaphragm 182.

It is contemplated that the second substrate 183 may be flexible toallow the substrate 183 to be mounted flush against the inner surface128 of the ocular implant 100. Alternatively, or additionally, thesecond substrate 183 may have a curved outer surface (facing away fromthe diaphragm 182) shaped to generally correspond to the curved innersurface 128 of the ocular implant 100. It is further contemplated thatthe materials forming the pressure sensor 180 may be selected such thatthe pressure sensor 180 is biocompatible.

As noted above, while the pressure sensor 180 has been described as aMEMS pressure sensor, it is contemplated that pressure sensor 180 maytake other suitable forms. In one alternative example, the pressuresensor may be formed in such a way that radio waves can be used todetect changes in pressure without sensor elements incorporated into thedevice. Such a pressure sensor may include a flexible base substrate, abottom inductive coil positioned on the base substrate, a layer ofpressure sensitive rubber pyramids positioned over the bottom inductivecoil, a top inductive coil positioned on top of the rubber pyramids, anda top substrate positioned over the top inductive coil. As a pressure isexerted on the sensor, the inductive coils move close together. Radiowaves (from an applied source) reflected by the inductive coils have alower resonance frequency when the coils are positioned closer together.Thus, the frequency of the radio waves can indicate the distance betweenthe coils which is then correlated to the pressure exerted on thedevice.

The pressure sensor 180 may be further provided with an antenna orinductor 184 to allow the data from the pressure sensor 180 to bewirelessly communicated to a readout device. In some instances, thepressure sensor 180 may use radiofrequency communication protocols, suchas, but not limited to cellular communication, ZigBee®, Bluetooth®,WiFi®, IrDA, dedicated short range communication (DSRC), EnOcean®, orany other suitable wireless protocols, as desired to transmit the datafrom the pressure sensor 180 to another device located outside the body.The data may be transmitted to any number so suitably enabled devices,including, but not limited to, cellular phones, tablet or laptopcomputers, desktop computers, portable handheld devices, such a personaldigital assistant (PDA), or a specially designed device, such as, butnot limited to a medical device. This may allow a physician, patient, orother interested party to monitor the ocular pressure without the use ofa tonometer. In some instances, the pressure data may be automaticallytransmitted to a physician from the remote device. For example, as shownin FIG. 11, once the ocular implant 100 with the pressure sensor 180 hasbeen implanted, an enabled remote device 192 may be brought withincommunication range of the patient's 190 eye. This may allow the enableddevice 192 to receive the ocular pressure data recorded at the pressuresensor 180. The enabled device 192 may be configured to automaticallytransmit the data to a physician, for example, to a second remotedevice.

FIG. 12 is a plan view showing an ocular implant 200 having a radius ofcurvature that varies along its length. A proximal end 201 of the ocularimplant 200 may include an interlocking portion configured to mate withand/or engage a complementary interlocking portion of a delivery tool.In the embodiment of FIG. 12, ocular implant 200 has an at rest shapethat is generally curved. This at rest shape can be established, forexample, using a heat-setting process. The ocular implant shape shown inFIG. 12 includes a distal radius RA, a proximal radius RC, and anintermediate radius RB. In the embodiment of FIG. 12, distal radius RAis larger than both intermediate radius RB and proximal radius RC. Alsoin the embodiment of FIG. 12, intermediate radius RB is larger thanproximal radius RC and smaller than distal radius RA. In one usefulembodiment, distal radius RA is about 0.320 inches (8.128 millimeters),intermediate radius RB is about 0.225 inches (5.715 millimeters) andproximal radius RC is about 0.205 inches (5.207 millimeters).

In the embodiment of FIG. 12, a distal portion of the ocular implantfollows an arc extending across an angle AA. A proximal portion of theocular implant follows an arc extending across an angle AC. Anintermediate portion of the ocular implant is disposed between theproximal portion and the distal portion. The intermediate portionextends across an angle AB. In one useful embodiment, angle AA is about55 degrees, angle AB is about 79 degrees and angle AC is about 60degrees.

Ocular implant 200 may be used in conjunction with a method of treatingthe eye of a human patient for a disease and/or disorder (e.g.,glaucoma). Some such methods may include the step of inserting a coremember into a lumen defined by ocular implant 200. The core member maycomprise, for example, a wire or tube. The distal end of the ocularimplant may be inserted into Schlemm's canal. The ocular implant and thecore member may then be advanced into Schlemm's canal until the ocularimplant has reached a desired position. In some embodiments, an inletportion of the implant may be disposed in the anterior chamber of eyewhile the remainder of the implant extends through the trabecular meshinto Schlemm's canal. The core member may then be withdrawn from theocular implant, leaving the implant in place to support tissue formingSchlemm's canal. Further details of ocular implant delivery systems maybe found in U.S. application Ser. No. 11/943,289, filed Nov. 20, 2007,now U.S. Pat. No. 8,512,404, the disclosure of which is incorporatedherein by reference.

The flexibility and bending modulus features of the ocular implant ofthis invention help ensure proper orientation of the implant withinSchlemm's canal. FIG. 1 shows the desired orientation of opening 124when the implant 100 is disposed in Schlemm's canal. As shown, opening124 faces radially outward. The implant 100 is therefore designed sothat it is maximally flexible when bent along a plane defined by thelongitudinal axis of implant 100 as shown in FIG. 1, and less flexiblewhen bent in other planes, thereby enabling the curved shape ofSchlemm's canal to help place the implant in this orientationautomatically if the implant is initially placed in Schlemm's canal in adifferent orientation.

FIG. 13 is a perspective view showing an ocular implant 300 inaccordance with an additional embodiment in accordance with the presentdetailed description. With reference to FIG. 13, it will be appreciatedthat ocular implant 300 has a resting (i.e., unstressed) shape that isgenerally straight. Ocular implant 300 extends along a longitudinal axis334 that is generally straight. In some useful embodiments, ocularimplant 300 is sufficiently flexible to assume a curved shape whenadvanced into Schlemm's canal of an eye.

Ocular implant 300 comprises a body 302. With reference to FIG. 13, itwill be appreciated that body 302 comprises a plurality of tissuesupporting frames 304 and a plurality of spines 306. As shown in FIG.13, these spines 306 and frames 304 are arranged in an alternatingpattern in which one spine extends between each adjacent pair of frames304. The frames 304 of body 302 include a first frame 336 of ocularimplant 300 is disposed between a first spine 340 and a second spine342. In the embodiment of FIG. 13, first frame 336 comprises a firststrut 344 that extends between first spine 340 and second spine 342. Asecond strut 346 of first frame also extends between first spine 340 andsecond spine 342. Each strut undulates in a circumferential direction asit extends longitudinally between first spine 340 and second spine 342.

An inner surface 328 of body 302 defines a channel 326. Body 302 ofocular implant 300 includes a first edge 320 and a second edge 322 thatdefine a first opening 324. Channel 326 of ocular implant 300 fluidlycommunicates with first opening 324. First strut 344 of first frame 336comprises a first edge 325A. Second strut 346 has a first edge 325B. InFIG. 13, first opening 324 in body 302 can be seen extending betweenfirst edge 325A of first strut 344 and a first edge 325B of second strut346.

A first axis 356, a second axis 358 and a third axis 360 are shown inFIG. 13. Second axis 358 is generally perpendicular to first axis 356.Third axis 360 is generally skewed relative to first axis 356. Theflexibility of body 302 is at a maximum when body 302 is bent by amoment acting about first axis 356, and body 302 has less flexibilitywhen bent by a moment acting about an axis other than first axis 356(e.g., second axis 358 and third axis 360). Stated another way, in theembodiment of FIG. 13, the bending modulus of body 302 is at a minimumwhen body 302 is bent by a moment acting about first axis 356, and body302 has a greater bending modulus when bent by a moment acting about anaxis other than first axis 356 (e.g., second axis 358 and third axis360).

The ocular implant 300 may further include an intraocular pressuresensor 380 mounted to the inner surface 328 of the ocular implant 300.The pressure sensor 380 may be similar in form and function to pressuresensor 180 described above. While the pressure sensor 380 is illustratedas mounted to an inner surface 328 of the ocular implant 300 it iscontemplated that the pressure sensor 380 may be mounted within one ofthe openings 324 or on an outer surface of the ocular implant 300, asdesired. The pressure sensor 380 may continuously measure theintraocular pressure of a patient, once the ocular implant 300 has beenimplanted.

The pressure sensor 380 may be a Micro-Electro-Mechanical System (MEMS)pressure sensor. While the pressure sensor 380 has been described as aMEMS pressure sensor, it is contemplated that other pressure sensors maybe used in place of, or in addition to, a MEMS pressure sensor. MEMSpressure sensors are often formed by anisotropically etching a recessinto a back side of a silicon substrate die, leaving a thin flexiblediaphragm. In operation, at least one surface of the diaphragm isexposed to an input pressure (e.g., the ocular pressure). The diaphragmdeflects according to the magnitude of the input pressure, which may bedetected by one or more electrical components or sense elements (e.g.,piezoresistors) positioned on or embedded within the diaphragm. Thechange in resistance of the piezoresistors is reflected as a change inan output voltage signal from a resistive bridge formed at least in partby the piezoresistors. In some cases, the diaphragm may be made thinnerwith the addition of support bosses, which may help increase thesensitivity of the diaphragm over a flat plate diaphragm. Circuitelements may be connected so that sensor elements to provide some levelof signal processing before providing an output signal to bond pads ofthe pressure sensor. The signal processing may filter, amplify,linearize, calibrate and/or otherwise process the raw sensor signalproduced by the sensor elements (e.g., piezoresistors). While the senseelements have been described as piezoresistors, it is contemplated thatthe sense elements may be selected to provide a capacitive pressuresensor 380.

The pressure sensor 380 may be further provided with an antenna orinductor to allow the data from the pressure sensor 380 to be wirelesslycommunicated to a readout device. In some instances, the pressure sensor380 may use radiofrequency communication protocols, such as, but notlimited to cellular communication, ZigBee®, Bluetooth®, WiFi®, IrDA,dedicated short range communication (DSRC), EnOcean®, or any othersuitable wireless protocols, as desired to transmit the data from thepressure sensor 380 to another device located outside the body. The datamay be transmitted to any number so suitably enabled devices, including,but not limited to, cellular phones, tablet computers, computers,portable handheld devices, such a personal digital assistant (PDA), or aspecially designed device. This may allow a physician, patient, or otherinterested party to monitor the ocular pressure without the use of atonometer.

FIG. 14 is a stylized representation of a medical procedure inaccordance with this detailed description. In the procedure of FIG. 14,a physician is treating an eye 400 of a patient P. In the procedure ofFIG. 14, the physician is holding a hand piece of a delivery system 450in his or her right hand RH. The physician's left hand (not shown) maybe used to hold the handle H of a gonio lens 402. Alternatively, somephysicians may prefer holding the delivery system hand piece in the lefthand and the gonio lens handle H in the right hand RH.

During the procedure illustrated in FIG. 14, the physician may view theinterior of the anterior chamber using gonio lens 402 and a microscope404. Detail A of FIG. 14 is a stylized simulation of the image viewed bythe physician. A distal portion of a cannula 452 is visible in Detail A.A shadow-like line indicates the location of Schlemm's canal SC which islying under various tissues (e.g., the trabecular meshwork) thatsurround the anterior chamber. A distal opening 454 of cannula 452 ispositioned near Schlemm's canal SC of eye 400.

Methods in accordance with this detailed description may include thestep of advancing the distal end of cannula 452 through the cornea ofeye 400 so that a distal portion of cannula 452 is disposed in theanterior chamber of the eye. Cannula 452 may then be used to accessSchlemm's canal of the eye, for example, by piercing the wall ofSchlemm's canal with the distal end of cannula 452. Distal opening 454of cannula 452 may be placed in fluid communication with a lumen definedby Schlemm's canal. The ocular implant may be advanced out of distalopening 454 and into Schlemm's canal. Insertion of the ocular implantinto Schlemm's canal may facilitate the flow of aqueous humor out of theanterior chamber of the eye.

FIG. 15 is an enlarged perspective view further illustrating deliverysystem 450 and eye 400 shown in the previous figure. In FIG. 15, cannula452 of delivery system 450 is shown extending through a cornea 426 ofeye 400. A distal portion of cannula 452 is disposed inside the anteriorchamber defined by cornea 426 of eye 400. In the embodiment of FIG. 15,cannula 452 is configured so that a distal opening 454 of cannula 452can be placed in fluid communication with Schlemm's canal.

In the embodiment of FIG. 15, an ocular implant is disposed in apassageway defined by cannula 452. Delivery system 450 includes amechanism that is capable of advancing and retracting the ocular implantalong the length of cannula 452. The ocular implant may be placed inSchlemm's canal of eye 400 by advancing the ocular implant through thedistal opening of cannula 452 while the distal opening is in fluidcommunication with Schlemm's canal.

FIG. 16A is a perspective view showing a delivery system 500 includingan ocular implant 550 and a cannula 508 defining a passageway that isdimensioned to slidingly receive ocular implant 550. Delivery system 500may be used to advance ocular implant 550 into a target location in theeye of a patient. Examples of target locations that may be suitable insome applications include areas in and around Schlemm's canal, thetrabecular meshwork, the suprachoroidal space, and the anterior chamberof the eye. FIG. 16B is an enlarged detail view further illustratingocular implant 550 and cannula 508 of delivery system 500.

Delivery system 500 of FIG. 16A is capable of controlling theadvancement and retraction of ocular implant 550 within cannula 508.Ocular implant 550 may be placed in a target location (e.g., Schlemm'scanal) by advancing the ocular implant through a distal opening 532 ofcannula 508 while the distal opening is in fluid communication withSchlemm's canal. In the embodiment of FIG. 16A, ocular implant 550 hasbeen advanced through distal opening 532 of cannula 508 for purposes ofillustration.

Delivery system 500 of FIG. 16A includes a housing 502, a sleeve 504,and an end cap 510. A tracking wheel 506 extends through a wall ofhousing 502 in FIG. 16A. Tracking wheel 506 is part of a mechanism thatis capable of advancing and retracting a delivery tool 552 of deliverysystem 500. The delivery tool 552 extends through a distal opening ofcannula 508 of FIG. 16B. Rotating the tracking wheel will cause deliverytool 552 to move in an axial direction along a passageway defined bycannula 508. The axial direction may be in a distal direction D or aproximal direction P. The delivery tool 552 and the mechanism for movingthe delivery tool 552 are described in commonly assigned applicationSer. No. 62/024,295, which is herein incorporated by reference.

In the embodiment of FIG. 16A, housing 502 is configured to be grippedwith one hand while providing control over the axial advancement andretraction of ocular implant via tracking wheel 506. The housing ofdelivery system 500 results in an advantageous ergonomic relationship ofthe fingers relative to the hand. This design provides a configurationthat will allow a user, such as a physician, to stabilize the deviceusing part of the hand, while leaving the middle or index finger freemove independently from the remainder of the hand. The middle or indexfinger is free to move independently to rotate the wheel for advancingand/or retract the ocular implant.

FIG. 16B is an enlarged detail view further illustrating ocular implant550 and a cannula 508 of delivery system 500. Cannula 508 comprises agenerally tubular member 598 having proximal portion 540, a distal end534, and a distal portion 544 extending between distal end 534 andproximal portion 540. In the embodiment of FIG. 6, distal portion 544 iscurved. In some useful embodiments, distal portion 544 is dimensionedand configured to be received in the anterior chamber of the eye.

FIG. 16B shows delivery tool 552 of delivery system 500 extendingthrough distal opening 532 of cannula 508. Delivery tool 552 includes aninterlocking portion 560 that is configured to form a connection with acomplementary interlocking portion 562 of ocular implant 550, asexplained in more detail below. In the embodiment of FIG. 16, rotatingthe tracking wheel will cause delivery tool 552 and ocular implant 550to move along a path defined by cannula 508. Cannula 508 is sized andconfigured so that the distal end of cannula 508 can be advanced throughthe trabecular meshwork of the eye and into Schlemm's canal. Positioningcannula 508 in this way places distal opening 532 in fluid communicationwith Schlemm's canal. Ocular implant 550 may be placed in Schlemm'scanal by advancing the ocular implant through distal opening 532 ofcannula 508 while the distal opening is in fluid communication withSchlemm's canal. The distal portion of the cannula may include a cuttingportion configured to cut through the trabecular meshwork and the wallof Schlemm's canal, such as by providing distal end 534 with a sharpedge adapted to cut through such tissue.

FIG. 17 is a perspective view of a cannula 508 in accordance with thepresent detailed description. Cannula 508 of FIG. 17 comprises agenerally tubular member 598 having a central axis 596. Generallytubular member 598 of FIG. 17 comprises a proximal portion 540, a distalend 534, and a distal portion 544 extending between distal end 534 andproximal portion 540. A distal opening surface 542 surrounds a distalopening 532 extending through the distal end 534 and through a side wallof cannula 508. A beveled edge 565 is disposed at the distal end ofdistal opening surface 542, extending from the distal end 534 to aproximal extent 567 of beveled edge 565. Tubular member 598 definesdistal opening 532, a proximal opening 536, and a passageway 538extending between proximal opening 536 and distal opening 532.

In the embodiment of FIG. 17, proximal portion 540 of cannula 508 issubstantially straight, distal portion 544 of cannula 508 is curved, andcentral axis 596 defines a curvature plane 548. Curvature plane 548 maybe referred to as a plane of curvature. Curvature plane 548 dividescannula 508 into a first portion PA and a second portion PB. In theembodiment of FIG. 17, second portion PB is substantially a mirror imageof first portion PA. In FIG. 17, distal portion 544 is shown extendingbetween distal end 534 and proximal portion 540 with no interveningelements. In the embodiment of FIG. 17, distal portion 544 is curvedalong its entire length.

A method in accordance with this detailed description may include thestep of advancing the distal end 534 of cannula 508 through the corneaof a human eye so that distal end 534 is disposed in the anteriorchamber of the eye. Cannula 508 may then be used to access Schlemm'scanal of the eye, for example, by piercing the wall of Schlemm's canalwith the distal end 534 of cannula 508. The beveled edge 565 may beinserted into Schlemm's canal to place at least part of distal opening532 of cannula 508 in communication with Schlemm's canal, as discussedin more detail below. The ocular implant may be advanced out of a distalport of the cannula and into Schlemm's canal.

In the embodiment of FIG. 17, distal portion 544 of cannula 508 definesa trough 554. In some useful embodiments, trough 554 is configured toreceive the entire external cross section of an ocular implant as theocular implant is being advanced into Schlemm's canal. When this is thecase, trough 554 may have a depth dimension that is deeper than a widthof the ocular implant. This cannula configuration advantageouslyprevents the ocular implant from intersecting the layers of thetrabecular meshwork as the ocular implant is advanced into Schlemm'scanal. Trough 554 may also be configured to allow the proximal portionof the ocular implant to be released from the delivery tool, asdiscussed below.

The cannula 508 may further include a pressure sensor 580 disposedwithin the trough 554. The pressure sensor 580 may be similar in formand function to pressure sensor 180 described above. While the pressuresensor 580 is illustrated as mounted within the trough 554 of thecannula, it is contemplated that the pressure sensor 580 may be mountedat other locations within or on the cannula 508. The pressure sensor 580may provide an instantaneous pressure reading during implantation of theocular implant 550 or shortly thereafter. In some instances, thepressure reading obtained from the pressure sensor 580 on the cannula508 can be compared to a pressure reading obtained from a pressuresensor mounted on the ocular implant 550, if so provided.

The pressure sensor 580 may be a Micro-Electro-Mechanical System (MEMS)pressure sensor. While the pressure sensor 580 has been described as aMEMS pressure sensor, it is contemplated that other pressure sensors maybe used in place of, or in addition to, a MEMS pressure sensor. Further,while only a single pressure sensor 580 has been illustrated, thecannula 508 may include more than one pressure sensor 580, as desired.MEMS pressure sensors are often formed by anisotropically etching arecess into a back side of a silicon substrate die, leaving a thinflexible diaphragm. In operation, at least one surface of the diaphragmis exposed to an input pressure (e.g., the ocular pressure). Thediaphragm deflects according to the magnitude of the input pressure,which may be detected by one or more electrical components or senseelements (e.g., piezoresistors) positioned on or embedded within thediaphragm. The change in resistance of the piezoresistors is reflectedas a change in an output voltage signal from a resistive bridge formedat least in part by the piezoresistors. In some cases, the diaphragm maybe made thinner with the addition of support bosses, which may helpincrease the sensitivity of the diaphragm over a flat plate diaphragm.Circuit elements may be connected so that sensor elements to providesome level of signal processing before providing an output signal tobond pads of the pressure sensor. The signal processing may filter,amplify, linearize, calibrate and/or otherwise process the raw sensorsignal produced by the sensor elements (e.g., piezoresistors). While thesense elements have been described as piezoresistors, it is contemplatedthat the sense elements may be selected to provide a capacitive pressuresensor 580.

The pressure sensor 580 may be further provided with an antenna orinductor to allow the data from the pressure sensor 580 to be wirelesslycommunicated to a readout device. In some instances, the pressure sensor580 may use radiofrequency communication protocols, such as, but notlimited to cellular communication, ZigBee®, Bluetooth®, WiFi®, IrDA,dedicated short range communication (DSRC), EnOcean®, or any othersuitable wireless protocols, as desired to transmit the data from thepressure sensor 580 to another device located outside the body. The datamay be transmitted to any number so suitably enabled devices, including,but not limited to, cellular phones, tablet computers, computers,portable handheld devices, such a personal digital assistant (PDA), or aspecially designed device. This may allow a physician, patient, or otherinterested party to monitor the ocular pressure without the use of atonometer.

FIG. 18 is a perspective view of an assembly including cannula 508 shownin the previous figure. For purposes of illustration, cannula 508 iscross-sectionally illustrated in FIG. 23. In FIG. 18, an ocular implant550 can be seen resting in a passageway 538 defined by cannula 508. Withreference to FIG. 18, it will be appreciated that distal portion 544 ofcannula 508 is curved so that central axis 596 of cannula 508 defines acurvature plane 548. With reference to FIG. 23, it will be appreciatedthat curvature plane 548 divides cannula 508 into a first portion and asecond portion PB. Only second portion PB of cannula 508 is shown in theillustrative embodiment of FIG. 18.

FIG. 19 is a stylized perspective view including the assembly shown inthe previous figure. In the embodiment of FIG. 19, a distal portion ofcannula 508 is shown extending through the wall of Schlemm's canal SC.The distal tip of cannula 508 may include a sharp portion configured forcutting and/or piercing the trabecular meshwork and the wall ofSchlemm's canal so that the passageway defined by the cannula can beplaced in fluid communication with the lumen defined by Schlemm's canal.With the passageway of the cannula placed in fluid communication withthe lumen of Schlemm's canal, ocular implant 550 can be advanced out ofthe distal opening of the cannula and into Schlemm's canal. In FIG. 19,a distal portion of ocular implant 550 can be seen through distalopening 532 of cannula 508.

For purposes of illustration, a hypothetical window W is cut through thewall of cannula 508 in FIG. 19. An interlocking portion 560 of adelivery tool 552 and a complementary interlocking portion 562 of ocularimplant 550 are visible through window W. In the embodiment of FIG. 19,interlocking portion 560 of delivery tool 552 and complementaryinterlocking portion 562 of ocular implant 550 are engaging each otherso that a proximal end 549 of ocular implant 550 is proximal to thedistal end 551 of delivery tool 552. Surface 561 of delivery tool 552rests against the wall of cannula 508 to prevent interlocking portion560 of delivery tool 552 and complementary interlocking portion 562 ofocular implant 550 from disengaging one another. When they are connectedin this fashion, delivery tool 552 and ocular implant 550 move togetheras the delivery tool is advanced and retracted relative to cannula 508by the delivery system mechanism.

FIG. 20 is an enlarged perspective view showing a portion of cannula 508shown in the previous figure. In some useful embodiments, cannula 508 iscurved to achieve substantially tangential entry into Schlemm's canalSC. In the embodiment of FIG. 20, cannula 508 is contacting an outermajor wall of Schlemm's canal SC at a point of tangency PT. Also in theembodiment of FIG. 20, a curved distal portion of cannula 508 isdimensioned to be disposed within the anterior chamber of the eye.

As shown in FIG. 20, the distal tip 534 and beveled edge of the cannula508 have been inserted into Schlemm's canal up to the proximal extent567 of beveled edge 565. In this position, ocular implant 550 can beseen extending into trough 554. In some useful embodiments, the ocularimplant has a radius of curvature that is larger than the radius ofcurvature of the cannula. This arrangement ensures that the ocularimplant will track along trough 554 as the ocular implant is urged in adistal direction by delivery system 500.

FIG. 21 is an additional perspective view showing ocular implant 550 andcannula 508 shown in the previous figure. By comparing FIG. 21 with theprevious figure, it will be appreciated that ocular implant 550 has beenadvanced in a distal direction D while cannula 508 has remainedstationary so that a distal portion of ocular implant 550 is disposedinside Schlemm's canal SC. Trough 554 opens into an elongate opening 532defined by edge 542 at the distal portion of cannula 508. In theembodiment of FIG. 21, the elongate opening defined by the cannulaprovides direct visualization of the ocular implant as it is advancedinto Schlemm's canal. A configuration allowing direct visualization ofthe ocular implant has a number of clinical advantages. During a medicalprocedure, it is often difficult to monitor the progress of the implantby viewing the implant through the trabecular meshwork. For example,blood reflux may push blood into Schlemm's canal obstructing aphysician's view the portion of the implant that has entered Schlemm'scanal. With reference to FIG. 21, ocular implant 550 tracks along trough554 as it is advanced distally along cannula 508. The trough openingallows the physician to monitor the progress of the implant by viewingthe implant structures as they advance through the trough prior toentering Schlemm's canal. The trough opening also allows the physicianto identify the position of the proximal end of the ocular implant withrespect to the incision made by the cannula to access Schlemm's canal.

FIG. 22 is an additional stylized perspective view showing ocularimplant 550 and cannula 508. In the embodiment of FIG. 22, theinterlocking portions 560 and 562 of the delivery tool 552 and ocularimplant 550, respectively, can be seen entering the distal opening 532defined by cannula 508. As shown, ocular implant 550 has been advancedin a distal direction D (relative to the embodiment shown in theprevious figure) so that more of ocular implant 550 is disposed insideSchlemm's canal SC. Surface 561 opposite interlocking portion 560 ofdelivery tool 552 still rests against the inner wall of cannula 508 tokeep the delivery tool interlocked with ocular implant 550.

FIG. 23 is an additional stylized perspective view showing ocularimplant 550 and cannula 508. As shown in FIG. 23, the ocular implant 550and delivery tool 552 have advanced further distally so that deliverytool surface 561 and part of the reduced diameter portion 563 have nowpassed into opening 532, thereby permitting the delivery tool curvedportion 553 to move toward its curved at-rest shape so that the deliverytool engagement surface 560 disengages and moves away from itscomplementary engagement surface 562 on the ocular implant 550.

In some useful embodiments, the delivery tool may be colored to providevisual differentiation from the implant. After the disengaging from theocular implant, cannula 508 and delivery tool 552 can be withdrawn fromSchlemm's canal SC leaving the ocular implant 550 in the fully deployedposition shown in FIG. 23. After delivery of ocular implant 550 iscomplete, the delivery tool and the cannula may be removed from the eye,leaving at least a distal portion of the ocular implant in Schlemm'scanal.

FIG. 24 is a perspective view of Schlemm's canal SC after the cannula(seen in the previous figure) has been withdrawn leaving an inletportion of ocular implant 550 in the anterior chamber of the eye and theremainder of ocular implant 550 in Schlemm's canal. The presence ofocular implant 550 in Schlemm's canal may facilitate the flow of aqueoushumor out of the anterior chamber. This flow may include axial flowalong Schlemm's canal, flow from the anterior chamber into Schlemm'scanal, and flow leaving Schlemm's canal via outlets communicating withSchlemm's canal. When in place within the eye, ocular implant 550 willsupport the trabecular meshwork and Schlemm's canal tissue and willprovide for improved communication between the anterior chamber andSchlemm's canal (via the trabecular meshwork) and between pockets orcompartments along Schlemm's canal.

In some instances, it may be desirable to deliver an ocular implant toSchlemm's canal in conjunction with another corrective surgery, such as,but not limited to, cataract surgery. When the ocular implant is placedduring another surgical procedure, it may be desirable to insert theocular implant through the same incision used for the other procedure.FIG. 25A is a perspective view showing another illustrative deliverysystem 600 that may be used to advance ocular implant 650 into a targetlocation in the eye of a patient through an incision location createdfor another procedure, such as, but not limited to cataract surgery. Thedelivery system 600 may include an ocular implant 650 and a cannula 608defining a passageway that is dimensioned to slidingly receive ocularimplant 650. It is contemplated that aspects of delivery system 600 maybe similar in form and function to delivery system 500. Examples oftarget locations that may be suitable in some applications include areasin and around Schlemm's canal, the trabecular meshwork, thesuprachoroidal space, and the anterior chamber of the eye. FIG. 25B isan enlarged detail view further illustrating ocular implant 650 andcannula 608 of delivery system 600.

Delivery system 600 of FIG. 25A is capable of controlling theadvancement and retraction of ocular implant 650 within cannula 608.Ocular implant 650 may be placed in a target location (e.g., Schlemm'scanal) by advancing the ocular implant 650 through a distal opening 632of cannula 608 while the distal opening is in fluid communication withSchlemm's canal. In the embodiment of FIG. 25A, ocular implant 650 hasbeen advanced through distal opening 632 of cannula 608 for purposes ofillustration.

Delivery system 600 of FIG. 25A includes a housing 602, a sleeve 604,and an end cap 610. A tracking wheel 606 extends through a wall ofhousing 602 in FIG. 25A. Tracking wheel 606 is part of a mechanism thatis capable of advancing and retracting a delivery tool 652 of deliverysystem 600. The delivery tool 652 is slidably disposed within cannula608 and configured to extend through a distal opening of cannula 608.Rotating the tracking wheel will cause delivery tool 652 to move in anaxial direction along a passageway defined by cannula 608. The axialdirection may be in a distal direction D or a proximal direction P.Delivery tool 652 may be similar in form and function to delivery tool152.

In the embodiment of FIG. 25A, housing 602 is configured to be grippedwith one hand while providing control over the axial advancement andretraction of ocular implant via tracking wheel 606. The features ofhousing 602 result in an advantageous ergonomic relationship of thefingers relative to the hand. This design provides a configuration thatwill allow a user, such as a physician, to stabilize the device usingpart of the hand, while leaving the middle or index finger free moveindependently from the remainder of the hand. The middle or index fingeris free to move independently to rotate the wheel for advancing and/orretract the ocular implant.

FIG. 25B is an enlarged detail view further illustrating ocular implant650 and a cannula 608 of delivery system 600. Cannula 608 comprises agenerally tubular member 698 having proximal portion 640, anintermediate portion 645, a distal portion 644, and a distal end 634.The intermediate portion 645 may extend distally from a first point 643distal to the proximal end 641 to a second point 647 proximal to thedistal end 634. The distal portion 644 may extend between distally fromthe second point 647 to distal end 634 of cannula 608 (shown in FIG.28). In the embodiment of FIG. 25, both distal portion 644 andintermediate portion 645 may be curved. In some instances, distalportion 644 may have a smaller radius of curvature, and thus a highercurvature, than the intermediate portion 645, although this is notrequired. In some useful embodiments, distal portion 644 andintermediate portion 645 may be dimensioned and configured to bereceived in the anterior chamber of the eye.

In some instances, it may be desirable to place the ocular implant 650during another ocular procedure, such as, but not limited to cataractsurgery. It is contemplated that the optimal position for an incisionfor cataract surgery may not be the same as the optimal position of anincision for solely placing an ocular implant, such as implant 650, intoSchlemm's canal. With previous ocular implant delivery system designs,in order to allow for substantially tangential entry of the cannula intoSchlemm's canal two separate incisions may be required when the implantis placed in combination with another ocular procedure. The curvedconfiguration of both the distal portion 644 may be configured to allowfor substantially tangential entry of the cannula 608 into Schlemm'scanal. It is further contemplated that the curved configuration of theintermediate portion 645 may allow the cannula 608 to be advancedthrough typical incisions associated with and/or optimized for cataractsurgery, such as, but not limited to, a sclerocorneal tunnel incision,while still allowing for substantially tangential entry of the cannula608 into Schlemm's canal. This may allow for two or more ocularprocedures to be performed using a single incision. It is furthercontemplated that performing multiple procedures through a singleincision may reduce patient discomfort and recovery time. FIG. 25B showsdelivery tool 652 of delivery system 600 extending through distalopening 632 of cannula 608. Delivery tool 652 includes an interlockingportion 660 that is configured to form a connection with a complementaryinterlocking portion 662 of ocular implant 650, as explained in moredetail below. In the embodiment of FIG. 25, rotating the tracking wheelwill cause delivery tool 652 and ocular implant 650 to move along a pathdefined by cannula 608. Cannula 608 is sized and configured so that thedistal end of cannula 608 can be advanced through the trabecularmeshwork of the eye and into Schlemm's canal. Positioning cannula 608 inthis way places distal opening 632 in fluid communication with Schlemm'scanal. Ocular implant 650 may be placed in Schlemm's canal by advancingthe ocular implant through distal opening 632 of cannula 608 while thedistal opening is in fluid communication with Schlemm's canal. Thedistal portion of the cannula 608 may include a cutting portionconfigured to cut through the trabecular meshwork and the wall ofSchlemm's canal, such as by providing distal end 634 with a sharp edgeadapted to cut through such tissue.

FIG. 26 is an enlarged perspective view further illustrating deliverysystem 600 shown in the previous figure and an eye 601. In FIG. 26,cannula 608 of delivery system 600 is shown extending through a cornea603 of eye 601. A distal portion of cannula 608 is disposed inside theanterior chamber defined by cornea 603 of eye 601. In the embodiment ofFIG. 26, cannula 608 is configured so that a distal opening 632 ofcannula 608 can be placed in fluid communication with Schlemm's canal.For example, distal portion 644 and intermediate portion 645 of cannula608 may be dimensioned and configured such that cannula 608 may beadvanced through an incision 607 created for another optical surgicalprocedure.

In the embodiment of FIG. 26, an ocular implant is disposed in apassageway defined by cannula 608. Delivery system 600 includes amechanism that is capable of advancing and retracting the ocular implantalong the length of cannula 608. The ocular implant may be placed inSchlemm's canal of eye 601 by advancing the ocular implant through thedistal opening of cannula 608 while the distal opening is in fluidcommunication with Schlemm's canal.

FIG. 27 is a perspective view further illustrating delivery system 600shown in the previous figure. In FIG. 27, a portion of housing 602 hasbeen removed for purposes of illustration. Delivery system 600 includesa delivery tool subassembly 670 and a cannula subassembly 680. Deliverytool subassembly 670 includes rotating rack gear 620 and a delivery tool(not shown). In the embodiment of FIG. 27, the delivery tool extendsinto a passageway defined by a cannula 608. Cannula 608 can be seenextending beyond sleeve 604 in FIG. 27. Cannula subassembly 680 includescannula 608, a hub 672, and an extension tube (not shown). In theembodiment of FIG. 27, the extension tube of cannula subassembly 680 isdisposed inside a lumen defined by rotating rack gear 620.

Delivery system 600 includes a mechanism 617 that controls the movementof delivery tool subassembly 670. Mechanism 617 includes a number ofcomponents that are located inside housing 602, including tracking wheel606, an idler gear 622, and the rotating rack gear 620. In theembodiment of FIG. 27, tracking wheel 606 and idler gear 622 are bothrotatably supported by housing 602. Gear teeth on tracking wheel 606engage gear teeth on idler gear 622, which in turn engage gear teeth onthe rotating rack gear 620. Rotating tracking wheel 606 in a counterclockwise direction CCW causes idler gear 622 to rotate in a clockwisedirection CW, which in turn causes the rotating rack gear 620 to move ina distal direction D. Rotating tracking wheel 606 in a clockwisedirection CW causes idler gear 622 to rotate in a counter clockwisedirection CCW, which in turn causes the rotating rack gear 620 to movein a proximal direction P. In other embodiments, the idler gear 622 maybe eliminated from the device, which would cause counter-clockwisemovement of the tracking wheel to move the rack gear proximally.

In the embodiment of FIG. 27, a sleeve 604 is fixed to cannulasubassembly 680. Sleeve 604 may be rotated by the user to change theorientation of cannula 608 with respect to housing 602. The sleeve 604may include gripping features, such as grooves (as shown), a rubbercoating, or other frictional surfaces to facilitate this use. In someapplications, correct alignment between the cannula and iris isadvantageous to ensure that the core tube and/or ocular implant isadvanced at the correct trajectory relative to Schlemm's canal or otheranatomy in the eye into which the ocular implant is to be implanted. Thedevice is configured in a manner that keeps the ocular implant alignedwithin the device during rotation. Selected groups of components arekeyed together to ensure that they rotate as a single body whilesimultaneously allowing axial movement of the ocular implant. In theembodiment of FIG. 27, cannula subassembly 680 and delivery toolsubassembly 670 may rotate in unison with sleeve 604 relative to housing602.

In the embodiment of FIG. 27, rotating rack gear 620 is configured torotate with sleeve 604 while maintaining the ability to move axially inthe distal and proximal directions before, during, and after rotation.As the rotating rack gear 620 moves distally and/or proximally, itcauses corresponding movement of the delivery tool relative to cannula608. This movement is transferred to ocular implant 650 when deliverytool 652 is coupled to ocular implant 650. Delivery tool subassembly 670and cannula subassembly 680 engage one another in a keyed arrangement,as described in more detail below. This keyed arrangement causesdelivery tool subassembly 670 and cannula subassembly 680 to maintain aconstant rotational orientation relative to each other while, at thesame time, allowing delivery tool subassembly 670 to translate in adistal direction D and a proximal direction P relative to cannulasubassembly 680.

In some embodiments, delivery tool 652 is formed from shape memorymaterial (such as, e.g., nitinol), and at least a portion of deliverytool 652 assumes a curved at-rest shape when no external forces areacting on it. Delivery tool 652 can be urged to assume a straightenedshape, for example, by inserting delivery tool 652 through a straightportion of the passageway defined by cannula 608. When the delivery tool652 is confined, such as within cannula 608, the interlocking portioncan engage the complementary interlocking portion to join the deliverytool and ocular implant together, and allow the delivery tool and ocularimplant to move together through the cannula 608, as described in moredetail below.

FIGS. 28, 29, and 30 illustrate more detailed views of cannula 608. FIG.28 is a side view of a cannula 608 in accordance with the presentdetailed description, FIG. 29 is an enlarged detail view of cannula 608,and FIG. 30 is an enlarged perspective view further illustrating aportion of distal portion 644 of cannula 608. Cannula 608 comprises agenerally tubular member 698 having a central axis 696. Generally,tubular member 698 comprises a proximal end 641, a proximal portion 640,an intermediate portion 645, a distal portion 644, and a distal end 634.Cannula 608 may extend a distance D1 between proximal end 641 and distalend 634. Tubular member 698 may have a length along central axis 696that is longer than distance D1 between proximal end 641 and distal end634. For purposes of example, It is contemplated that distance D1 may bein the range of 1.50 to 3.50 inches (3.81 to 8.89 centimeters), 2.0 to3.0 inches (5.08 to 7.62 centimeters) or around 2.50 inches (6.35centimeters). It is contemplated cannula 608 may span any distance D1desired. Proximal portion 640 may extend over a distance D2 fromproximal end 641 to a point 643 distal to proximal end 641. Proximalportion 640 may be generally straight such that distance D2 isapproximately equal to or equal to a length of proximal portion 640measured along central axis 696. Distance D2 may be in the range of 1.50to 2.50 inches (3.81 to 6.35 centimeters), 1.75 to 2.25 inches (4.652 to5.72 centimeters), or around 2.0 inches (5.08 centimeters). Intermediateportion 645 may extend between first point 643 and a second point 647located proximal to distal end 634 of cannula 608. Intermediate portion645 may span a distance D3 extending from point 643 and point 647.Distance D3 may be in the range of 0.15 to 0.50 inches (0.38 to 1.27centimeters), 0.25 to 0.40 inches (0.64 to 1.02 centimeters), or around0.33 inches (0.84 centimeters). Intermediate portion 645 may have alength along central axis 696 of tubular member 698 that is longer thandistance D3. The difference in the length of intermediate portion 645and the distance D3 may be determined by the degree of curvature ofintermediate portion 645, as will be discussed in more detail below.Distal portion 644 may extend between second point 647 and distal end634. Distal portion 644 may span a distance D4 extending from point 647and distal end point 634. Distance D4 may be in the range of 0.05 to0.30 inches (0.13 to 0.76 centimeters), 0.13 to 0.23 inches (0.33 to0.58 centimeters), or around 0.17 inches (0.43 centimeters). Distalportion 644 may have a length along central axis 696 of tubular member698 that is longer than distance D4. The difference in the length ofdistal portion 644 and the distance D4 may be determined by the degreeof curvature of distal portion 644, as will be discussed in more detailbelow.

A distal opening surface 642 surrounds a distal opening 632 extendingthrough the distal end 634 and through a side wall of cannula 608. Abeveled edge 665 is disposed at the distal end of distal opening surface642, extending from the distal end 634 to a proximal extent 667 ofbeveled edge 665. Tubular member 698 defines distal opening 632, aproximal opening 636, and a passageway 638 extending between proximalopening 636 and distal opening 632.

Proximal portion 640 of cannula 608 is substantially straight whileintermediate portion 645 and distal portion 644 of cannula 608 may becurved. In the embodiment of FIG. 28, distal portion 644 is curved alongits entire length and intermediate portion 645 is curved along itsentire length. Intermediate portion 645 may define a curve having afirst radius R1 measured from central axis 696 and defining a firstradius of curvature. The length of intermediate portion 645 alongcentral axis 696 may be determined by the measure of the arc (indegrees) and the radius of the curve using Equation 1 below:

$\begin{matrix}{L_{arc} = {{\theta( \frac{\pi}{180} )}r}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

where L_(arc) is the length of the arc, θ is the angle measure of thearc (in degrees), and r is the radius of the circle. In some instances,the angle measure of intermediate portion 645 may be in the range of 10°to 25°, although other angles are possible. Distal portion 644 maydefine a curve having a second radius R2 and defining a second radius ofcurvature. The length of distal portion 644 along central axis 696 maybe determined by the measure of the arc (in degrees) and the radius ofthe curve using Equation 1 above. In some instances, the angle measureof distal portion 644 may be in the range of 90° to 110°, although otherangles are possible. It is contemplated that the first radius R1 may belarger than the second radius R2 such that the distal portion 644 has ahigher curvature than the intermediate portion 645. This configurationmay advance the ocular implant at the correct trajectory relative toSchlemm's canal or other anatomy in the eye into which the ocularimplant is to be implanted. For example, the configuration may allow thecannula 608 to be advanced through an incision generally along a majoraxis of the visible eye and allowing for substantially tangential entryof cannula 608 into Schlemm's canal. It is contemplated that firstradius R1 and second radius R2 may be selected to facilitate delivery ofimplant 650 to other anatomical locations.

FIG. 28A is an additional side view and illustrates a sectioned view ofthe cannula shown in FIG. 25. For purposes of example, cannula 608comprises a generally tubular member 698 having a central axis 696.Generally tubular member 698 comprises a proximal end 641, a proximalportion 640, an intermediate portion 645, a distal portion 644, and adistal end 634. Additionally, for example, the central axis 696 ofproximal portion 640 is tangential to the tangential line at first point643 of intermediate portion 645. Further, the tangential line at secondpoint 647 of intermediate portion 645 is tangential to the tangentialline of the second point 647 of distal portion 644. The tangential lineat distal end 634 of distal portion 644 and the central axis 696 ofproximal portion may have third radius R3, for example, having an angleapproximately in the range of 90° to 165°.

A method in accordance with this detailed description may include thestep of advancing the distal end 634 of cannula 608 through the corneaof a human eye so that distal end 634 is disposed in the anteriorchamber of the eye. Cannula 608 may then be used to access Schlemm'scanal of the eye, for example, by piercing the wall of Schlemm's canalwith the distal end 634 of cannula 608. The beveled edge 665 may beinserted into Schlemm's canal to place at least part of distal opening632 of cannula 608 in communication with Schlemm's canal. For example,cannula 608 may be advanced until the distal tip 634 and beveled edge665 of cannula 608 have been inserted into Schlemm's canal up to theproximal extent 667 of beveled edge 665. With the passageway of thecannula 608 placed in fluid communication with the lumen of Schlemm'scanal, the ocular implant may be advanced out of a distal port of thecannula 608 and into Schlemm's canal.

In the embodiment of FIG. 29 and further illustrated in FIG. 30, distalportion 644 of cannula 608 defines a trough 654. In some embodiments,trough 654 is configured to receive the entire external cross section ofan ocular implant as the ocular implant is being advanced into Schlemm'scanal. When this is the case, trough 654 may have a depth dimension thatis deeper than a width of the ocular implant. This cannula configurationadvantageously prevents the ocular implant from intersecting the layersof the trabecular meshwork as the ocular implant is advanced intoSchlemm's canal. Trough 654 may also be configured to allow the proximalportion of the ocular implant to be released from the delivery tool in amanner similar to trough 554 described above.

Referring briefly to FIG. 25B, while not explicitly shown, duringadvancement of ocular implant 650 interlocking portion 660 of deliverytool 652 and complementary interlocking portion 662 of ocular implant650 may be engaged with each other so that a proximal end of ocularimplant 650 is proximal to the distal end of delivery tool 652. Surface661 of delivery tool 652 rests against the wall of cannula 608 toprevent interlocking portion 660 of delivery tool 652 and complementaryinterlocking portion 662 of ocular implant 650 from disengaging oneanother. When they are connected in this fashion, delivery tool 652 andocular implant 650 move together as the delivery tool is advanced andretracted relative to cannula 608 by the delivery system mechanism. Insome embodiments, the ocular implant 650 has a radius of curvature thatis larger than the radius of curvature of the distal portion 644 ofcannula 608. This arrangement ensures that the ocular implant will trackalong trough 654 as the ocular implant is urged in a distal direction bydelivery system 600.

Once cannula 608 has been positioned in the desired location, ocularimplant 650 may be advanced distally while cannula 608 is heldstationary. Elongate opening 632 may provide direct visualization ofocular implant 650 as it is advanced into Schlemm's canal. Aconfiguration allowing direct visualization of the ocular implant has anumber of clinical advantages. During a medical procedure, it is oftendifficult to monitor the progress of the implant by viewing the implantthrough the trabecular meshwork. For example, blood reflux may pushblood into Schlemm's canal obstructing a physician's view the portion ofthe implant that has entered Schlemm's canal. Ocular implant 650 tracksalong trough 654 as it is advanced distally along cannula 608. Thetrough opening allows the physician to monitor the progress of theimplant by viewing the implant structures as they advance through thetrough prior to entering Schlemm's canal. The trough opening also allowsthe physician to identify the position of the proximal end of the ocularimplant with respect to the incision made by the cannula to accessSchlemm's canal.

Delivery tool 652 may advance ocular implant 650 distally until deliverytool surface 661 and part of the reduced diameter portion 663 have nowpassed into opening 632, thereby permitting the delivery tool curvedportion to move toward its curved at-rest shape so that the deliverytool engagement surface 660 disengages and moves away from itscomplementary engagement surface 662 on the ocular implant 650. Afterthe disengaging from the ocular implant, cannula 608 and delivery tool652 can be withdrawn from Schlemm's canal leaving the ocular implant 650in the fully deployed position. After delivery of ocular implant 650 iscomplete, the delivery tool 652 and the cannula 608 may be removed fromthe eye, leaving at least a distal portion of the ocular implant 650 inSchlemm's canal. An inlet portion of ocular implant 650 may bepositioned in the anterior chamber of the eye and the remainder ofocular implant 650 in Schlemm's canal. The presence of ocular implant650 in Schlemm's canal may facilitate the flow of aqueous humor out ofthe anterior chamber. This flow may include axial flow along Schlemm'scanal, flow from the anterior chamber into Schlemm's canal, and flowleaving Schlemm's canal via outlets communicating with Schlemm's canal.When in place within the eye, ocular implant 650 will support thetrabecular meshwork and Schlemm's canal tissue and will provide forimproved communication between the anterior chamber and Schlemm's canal(via the trabecular meshwork) and between pockets or compartments alongSchlemm's canal.

The cannula 608 may further include a pressure sensor 690 disposedwithin the trough 654. The pressure sensor 690 may be similar in formand function to pressure sensor 180 described above. While the pressuresensor 690 is illustrated as mounted within the trough 654 of thecannula, it is contemplated that the pressure sensor 690 may be mountedat other locations within or on the cannula 608. The pressure sensor 690may provide an instantaneous pressure reading during implantation of theocular implant 650 or shortly thereafter. In some instances, thepressure reading obtained from the pressure sensor 690 on the cannula608 can be compared to a pressure reading obtained from a pressuresensor mounted on the ocular implant 650, if so provided.

The pressure sensor 690 may be a Micro-Electro-Mechanical System (MEMS)pressure sensor. While the pressure sensor 690 has been described as aMEMS pressure sensor, it is contemplated that other pressure sensors maybe used in place of, or in addition to, a MEMS pressure sensor. Further,while only a single pressure sensor 690 has been illustrated, thecannula 608 may include more than one pressure sensor 690, as desired.MEMS pressure sensors are often formed by anisotropically etching arecess into a back side of a silicon substrate die, leaving a thinflexible diaphragm. In operation, at least one surface of the diaphragmis exposed to an input pressure (e.g., the ocular pressure). Thediaphragm deflects according to the magnitude of the input pressure,which may be detected by one or more electrical components or senseelements (e.g., piezoresistors) positioned on or embedded within thediaphragm. The change in resistance of the piezoresistors is reflectedas a change in an output voltage signal from a resistive bridge formedat least in part by the piezoresistors. In some cases, the diaphragm maybe made thinner with the addition of support bosses, which may helpincrease the sensitivity of the diaphragm over a flat plate diaphragm.Circuit elements may be connected so that sensor elements to providesome level of signal processing before providing an output signal tobond pads of the pressure sensor. The signal processing may filter,amplify, linearize, calibrate and/or otherwise process the raw sensorsignal produced by the sensor elements (e.g., piezoresistors). While thesense elements have been described as piezoresistors, it is contemplatedthat the sense elements may be selected to provide a capacitive pressuresensor 690.

The pressure sensor 690 may be further provided with an antenna orinductor to allow the data from the pressure sensor 690 to be wirelesslycommunicated to a readout device. In some instances, the pressure sensor690 may use radiofrequency communication protocols, such as, but notlimited to cellular communication, ZigBee®, Bluetooth®, WiFi®, IrDA,dedicated short range communication (DSRC), EnOcean®, or any othersuitable wireless protocols, as desired to transmit the data from thepressure sensor 690 to another device located outside the body. The datamay be transmitted to any number so suitably enabled devices, including,but not limited to, cellular phones, tablet computers, computers,portable handheld devices, such a personal digital assistant (PDA), or aspecially designed device. This may allow a physician, patient, or otherinterested party to monitor the ocular pressure without the use of atonometer.

Components of ocular device may be made from a metal, metal alloy,polymer (some examples of which are disclosed below), a metal-polymercomposite, ceramics, combinations thereof, and the like, or othersuitable material. Some examples of suitable polymers may includepolytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE),fluorinated ethylene propylene (FEP), polyoxymethylene (POM, forexample, DELRIN® available from DuPont), polyether block ester,polyurethane (for example, Polyurethane 85A), polypropylene (PP),polyvinylchloride (PVC), polyether-ester (for example, ARNITEL®available from DSM Engineering Plastics), ether or ester basedcopolymers (for example, utylene/poly(alkylene ether) phthalate and/orother polyester elastomers such as HYTREL® available from DuPont),polyamide (for example, DURETHAN® available from Bayer or CRISTAMID®available from Elf Atochem), elastomeric polyamides, blockpolyamide/ethers, polyether block amide (PEBA, for example availableunder the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA),silicones, polyethylene (PE), Marlex high-density polyethylene, Marlexlow-density polyethylene, linear low density polyethylene (for exampleREXELL®), polyester, polybutylene terephthalate (PBT), polyethyleneterephthalate (PET), polytrimethylene terephthalate, polyethylenenaphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI),polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide(PPO), poly paraphenylene terephthalamide (for example, KEVLAR®),polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMSAmerican Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinylalcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC),poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS50A), polycarbonates, ionomers, biocompatible polymers, other suitablematerials, or mixtures, combinations, copolymers thereof, polymer/metalcomposites, and the like. In some embodiments the sheath can be blendedwith a liquid crystal polymer (LCP). For example, the mixture cancontain up to about 6 percent LCP.

Some examples of suitable metals and metal alloys include stainlesssteel, such as 304V, 304L, and 316LV stainless steel; mild steel;nickel-titanium alloy such as linear-elastic and/or super-elasticnitinol; other nickel alloys such as nickel-chromium-molybdenum alloys(e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY®C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys,and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL®400, NICKELVAC® 400, NICORROS® 400, and the like),nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such asMP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 suchas HASTELLOY® ALLOY B2®), other nickel-chromium alloys, othernickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-ironalloys, other nickel-copper alloys, other nickel-tungsten or tungstenalloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenumalloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like);platinum enriched stainless steel; titanium; combinations thereof; andthe like; or any other suitable material.

As alluded to herein, within the family of commercially availablenickel-titanium or nitinol alloys, is a category designated “linearelastic” or “non-super-elastic” which, although may be similar inchemistry to conventional shape memory and super elastic varieties, mayexhibit distinct and useful mechanical properties. Linear elastic and/ornon-super-elastic nitinol may be distinguished from super elasticnitinol in that the linear elastic and/or non-super-elastic nitinol doesnot display a substantial “superelastic plateau” or “flag region” in itsstress/strain curve like super elastic nitinol does. Instead, in thelinear elastic and/or non-super-elastic nitinol, as recoverable strainincreases, the stress continues to increase in a substantially linear,or a somewhat, but not necessarily entirely linear relationship untilplastic deformation begins or at least in a relationship that is morelinear that the super elastic plateau and/or flag region that may beseen with super elastic nitinol. Thus, for the purposes of thisdisclosure linear elastic and/or non-super-elastic nitinol may also betermed “substantially” linear elastic and/or non-super-elastic nitinol.

In some cases, linear elastic and/or non-super-elastic nitinol may alsobe distinguishable from super elastic nitinol in that linear elasticand/or non-super-elastic nitinol may accept up to about 2-5% strainwhile remaining substantially elastic (e.g., before plasticallydeforming) whereas super elastic nitinol may accept up to about 8%strain before plastically deforming. Both of these materials can bedistinguished from other linear elastic materials such as stainlesssteel (that also can be distinguished based on its composition), whichmay accept only about 0.2 to 0.44 percent strain before plasticallydeforming.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy is an alloy that does not show anymartensite/austenite phase changes that are detectable by differentialscanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA)analysis over a large temperature range. For example, in someembodiments, there may be no martensite/austenite phase changesdetectable by DSC and DMTA analysis in the range of about −60 degreesCelsius (° C.) to about 120° C. in the linear elastic and/ornon-super-elastic nickel-titanium alloy. The mechanical bendingproperties of such material may therefore be generally inert to theeffect of temperature over this very broad range of temperature. In someembodiments, the mechanical bending properties of the linear elasticand/or non-super-elastic nickel-titanium alloy at ambient or roomtemperature are substantially the same as the mechanical properties atbody temperature, for example, in that they do not display asuper-elastic plateau and/or flag region. In other words, across a broadtemperature range, the linear elastic and/or non-super-elasticnickel-titanium alloy maintains its linear elastic and/ornon-super-elastic characteristics and/or properties.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy may be in the range of about 50 to about 60 weightpercent nickel, with the remainder being essentially titanium. In someembodiments, the composition is in the range of about 54 to about 57weight percent nickel. One example of a suitable nickel-titanium alloyis FHP-NT alloy commercially available from Furukawa Techno Material Co.of Kanagawa, Japan. Some examples of nickel titanium alloys aredisclosed in U.S. Pat. Nos. 5,238,004 and 6,508,803, which areincorporated herein by reference. Other suitable materials may includeULTANIUM™ (available from Neo-Metrics) and GUM METAL™ (available fromToyota). In some other embodiments, a superelastic alloy, for example asuperelastic nitinol can be used to achieve desired properties.

It is to be understood that even though numerous characteristics ofvarious embodiments have been set forth in the foregoing description,together with details of the structure and function of variousembodiments, this detailed description is illustrative only, and changesmay be made in detail, especially in matters of structure andarrangements of parts illustrated by the various embodiments to the fullextent indicated by the broad general meaning of the terms in which theappended claims are expressed.

What is claimed is:
 1. An ocular implant kit, the kit comprising: anocular implant adapted to reside at least partially in a portion ofSchlemm's canal of an eye, the implant comprising: a tubular body havingan inner surface and an outer surface, the tubular body extending in acurved volume whose longitudinal axis forms an arc of a circle, thetubular body having a diameter of between 0.005 inches and 0.04 inches;a plurality of open areas and strut areas formed in the tubular body,the strut areas surrounding the plurality of open areas; a firstpressure sensor disposed on the inner surface of the tubular bodyadjacent an opening of the plurality of openings, the pressure sensorcomprising a diaphragm facing the elongate channel and a piezoresistordisposed on the diaphragm; and a cannula defining a passageway extendingfrom a proximal end to a distal end, the cannula having a distal openingextending through a side wall and the distal end of the cannula to forma trough, a curved distal portion, a curved intermediate portion, and aproximal portion; and a delivery tool having a distal interlockingportion engaging a complementary interlocking portion of the ocularimplant.
 2. The kit of claim 1, wherein the first pressure sensorfurther comprises a first substrate comprising a layered siliconsubstrate and a cavity, the diaphragm being disposed over the cavity,and a second substrate comprising a semiconductor wafer.
 3. The kit ofclaim 1, wherein the first pressure sensor includes an antenna fortransmitting data from the first pressure sensor to a remote location.4. The kit of claim 3, wherein the data is automatically transmittedfrom the remote location to a second remote device.
 5. The kit of claim1, further comprising a second pressure sensor disposed within thetrough of the cannula.
 6. The kit of claim 5, wherein the secondpressure sensor comprises a micro-electro-mechanical system (MEMS)pressure sensor and includes an antenna for transmitting data from thesecond pressure sensor to a remote location.